1. Field of the Invention
The present invention relates to a fuel injection device, in which fuel in a fuel tank is increased in pressure by a fuel pump, and the fuel increased in pressure is injected toward an engine through a fuel injection valve. More particularly, the present invention relates to a link type throttle valve control device for opening/closing a throttle valve of the throttle body through a link mechanism, where the throttle valve controls air content toward the engine. The link type throttle valve control device is used when opening characteristics with respect to a pulling margin of an accelerator wire is changed.
2. Description of the Conventional Art
A conventional link type throttle valve control device in a throttle body is illustrated in FIGS. 6 and 7.
FIG. 6 is a side view of a link type throttle valve control device, and FIG. 7 is a longitudinal sectional view taken along a line C—C in FIG. 6.
Reference numeral 50 is a throttle body in which an intake passage 51 is provided through inside thereof, and a throttle valve shaft 52 is supported rotatably to a throttle body 50 while crossing the intake passage 51.
A butterfly shaped throttle valve 53 is mounted at a throttle valve shaft 52 by a screw 54, and the throttle valve shaft 52 is rotated in one or reverse direction, to thereby open/close the intake passage 51 by the throttle valve 53.
In FIG. 7, a right end of the throttle valve shaft 52 is projected toward the right side further from an end portion of a right side bearing boss 50a. A return lever 55 and a second link lever 56 are fixedly mounted at the right end of the throttle valve shaft
More particularly, a D shaped cutout portion 52a is formed at the right end of the throttle valve shaft 52, and D cut holes 55a, 56a are provided at the return lever 55 and the second link lever 56, where these holes are fitted to the cutout portion 52a. The D cut hole 55a of the return lever 55 is fitted to the cutout portion 52a of the throttle valve shaft 52, and the D cut hole 56a of the second link lever 56 is fitted to the cutout portion 52a of the throttle valve shaft 52. In this state, the return lever 55 and the second link lever 56 are screwed and fixed at the right end of the throttle valve shaft 52 by a screw nut 58 through a collar 57.
That is, the return lever 55 and the second link lever 56 are simultaneously rotated.
Reference numeral 59 is first return spring, where one end is locked with the throttle body 50 and another end is locked with the return lever 55. The first return spring 59 gives rotating force to the return lever 55 in the clockwise direction in FIG. 6. (This rotating force is energizing force in the closing direction to the throttle valve 53, and the throttle valve 53 opens the intake passage 51 when rotating in the counterclockwise in FIG. 6.)
Further, an operation bearing boss 50c extending toward the right side is integrally formed at an upper portion of a wall portion 50b, which extends upwardly from the throttle body 50. A throttle valve operation shaft 60 is supported rotatably in an operation bearing hole 50d provided at the operation bearing boss 50c. 
A right end of the throttle valve operation shaft 60 is projected toward right further from a right end of 50ca of the operation bearing boss 50c, and the projected portion is mounted fixedly with a throttle valve operation dram 61 and a first link lever 62 by a nut 63. Therefore, the throttle valve operation dram 61 and the first link lever 62 are simultaneously rotated.
Mounting method for the throttle valve operation dram 61 and the first link lever 62 to the throttle valve operation shaft 60 is carried out like the return lever 55 and the second link lever 56.
A valve opening end inserting hole 61a and a valve closing end inserting hole 61b are provided at the throttle valve operation dram.
Further, the first link lever 62 and the second link lever 56 are connected with a connection lever 63a so as to move to interlock each other. A link mechanism R is formed with the first link lever 62, the second link lever 56 and the connection lever 63a. 
Further, reference numeral 64 is a stay plate formed by bending a metal plate. The stay plate 64 is screwed and fixed at a boss portion 50g of the throttle body 50 being near the operation bearing boss 50c by a screw 69.
A first cable guide inserting hole 64a and a second cable guide inserting hole 64b are formed on the stay plate 64, where the hole 64a faces to the valve opening end inserting hole 61a, and the hole 64b faces to the valve closing end inserting hole 61. Further, an accelerator grip, which is not illustrated in the drawings, and the throttle valve operation dram 61 are connected as follows.
Reference numeral 65 is a first cable guide, which is inserted and provided in the first cable guide inserting hole 64a and held by the stay plate 64 with nuts 66a, 66b. A valve opening wire end Wa1 is provided at one end of the opening valve wire Wa inserted and provided in the first cable guide 65, and inserted and locked in the closing valve end inserting hole 61a of the throttle valve operation dram 61, and another end is locked with the accelerator grip which is not illustrated in the drawings.
Reference numeral 67 is a second cable guide, which is inserted and provided in the second cable guide inserting hole 64b and held by the stay plate 64 with nuts 68a, 68b. A valve closing wire end Wb1 is provided at one end of the closing valve wire Wb inserted and provided in the second cable guide 67, and inserted and locked in the closing valve end inserting hole 61b of the throttle valve operation dram 61, and another end is locked with the accelerator grip which is not illustrated in the drawings.
Reference numeral 69 is a return spring, in which one end is locked with the stay plate 64 and another end is locked with the throttle valve operation dram 61. The throttle valve operation dram 61 is energized in the counterclockwise direction in FIG. 6 by the second return spring 69.